1. Field of Invention
This invention relates to postal mailboxes, specifically to mail delivery indicator systems.
2. Prior Art
Waiting for mail to be delivered can often turn into a nerve wracking experience requiring many futile trips to the roadside mailbox. The patent search for the present invention traces as far back as to U.S. Pat. No. 792,133 issued to J. W. Hunt (1905) and also to U.S. Pat. No. 1,292,050 issued to H. W. Raney (1919). In the wake of these early inventions, many U.S. patents have been issued to cover a wide range of inventions that were designed to produce a timely signal when mail is delivered. They can be grouped into the following four broad classifications based on the primary activation mechanism of each invention—gravity activated mechanisms, spring activated mechanisms, leverage activated mechanisms, and electric and electronic activated mechanisms. Because the present invention operates on the principle of gravity, the search and evaluation of the relevant prior art have primarily been directed to the following fourteen prominent inventions that utilize gravity activated mechanisms:
U.S. Pat. No. 2,352,975 to Roe (1944), U.S. Pat. No. 2,804,262 to Mancuso (1957), U.S. Pat. No. 2,988,268 to Mioduski (1961), U.S. Pat. No. 3,747,839 to Morton (1973), U.S. Pat. No. 3,960,317 to Clement (1976), U.S. Pat. No. 4,190,193 to Smith (1980), U.S. Pat. No. 4,752,030 to Witt (1988), U.S. Pat. No. 4,756,472 to Hammons (1988), U.S. Pat. No. 4,759,496 to Swick (1988), U.S. Pat. No. 4,811,895 to Reinebach (1989), U.S. Pat. No. 4,821,953 to Poloha (1989), U.S. Pat. No. 4,836,441 to Crider (1989), U.S. Pat. No. 5,660,327 to Brinkley (1997), and 20010000108 to Perry (2001).
Among the inventions based on the gravity activated mechanisms cited above, U.S. Pat. No. 4,756,472 issued to Hammons, whose abstract is cited below, represents a typical application of the gravity activated mechanism to produce a signal by traversing the flagged end of their indicator arm toward the mailbox front door when the mailbox front door is opened, but any similarity with the present invention quickly ends there because the present invention makes a contrary directional movement of the indicator flag element away from the mailbox front door to indicate that the mail has arrived.
Title: Mail delivery signaling flag
U.S. Pat. No. 4,756,472
Inventors: Hammons; George M. Issued: Jul. 12, 1988
The specification discloses a mail delivery signaling flag for use on a rural mailbox including an elongate indicator arm. The indicator arm has a weighted end and a flagged end and is rotatably mounted to the side of the mailbox. A trigger means holds the indicator arm in a generally horizontal position until the mailbox door is opened, at which time the indicator arm assumes a generally vertical position with the flagged end raised to indicate that a mail carrier has opened the box.
The following two inventions are also noteworthy because they incorporate the movement of a flagstaff away from the mailbox front door, as does the present invention, but utilize spring activated mechanisms.
Title: Mail delivery indicator for a mailbox
U.S. Pat. No. 5,123,590
Inventors: Teele; A. James Issued: Jun. 23, 1992
A mail delivery indicator which may be readily and easily mounted on the standard rural or cluster mailbox to signal when the mail has been delivered by the mail carrier. The mail delivery indicator comprises an elongated rod forming a flagstaff with one of its ends connected to a coiled spring attached by a bracket to the right side of the mailbox. The other end of the flagstaff is provided with a flag member and a latch element. The latch element serves the dual purpose of securing the flag to the flagstaff and engaging a catch element on the mailbox front door to set the flagstaff in its horizontal non-signaling position when the door is closed. When the door is opened by the mail carrier, the latch element releases from the catch element and the coiled spring causes flagstaff to automatically swing to its vertical signaling position. The flag can be rotatably positioned on the flagstaff to permit optimum viewing and is also provided with a specially designed offset portion which clears the catch element as the flagstaff swings upwardly.
Title: Mailbox indicator system
U.S. Pat. No. 5,964,401
Inventors: Thill; Gene R. Issued: Oct. 12, 1999
A mailbox indicator system includes a flag post having a flag attached to the post by a removable collar. The post is further attached to an elbow member by a coil. The elbow member is attachable to a wall of a mailbox. The coil urges the post into a substantially vertical position. A retention assembly is provided for holding the post in a substantially horizontal orientation when in a set position. The retention assembly is attached to the door of the mailbox such that the post disengages the retention assembly when the mailbox door is opened. In an alternate embodiment, the mailbox indicating system includes a spacer to selectively position the post retention assembly in spaced relationship to the mailbox door such that a mailbox protrusion proximate the mailbox door does not interfere with engagement of the post to the post retention assembly. The elbow member is attachable to the mailbox using a bolt and nut holding a pair of rubber washers around a wall of the mailbox. Preferably, a pair of metal washers are positioned around the rubber washers
In U.S. Pat. No. 4,756,472 issued to Hammons, a trigger arm is fastened to the front door to hold the weighted end of an elongated indicator arm in a somewhat horizontal non-signaling position when the mailbox front door is closed. When the mail carrier pulls open the mailbox front door, the trigger means releases the weighted end of the indicator arm which is designed to fall downwardly by the gravity force of its weight and the flagged end of the indicator arm is designed to traverse rotationally forward toward the mailbox front door. The forward movement of the flagged end of the elongated indicator arm may startle the mail carrier and may not be desirable for safety reasons.
A backward movement of the flagged end of an elongated indicator rod away from the mail carrier was adopted in U.S. Pat. No. 5,123,590 issued to Teele and U.S. Pat. No. 5,964,401 issued to Thill. But their inventions rely on a coiled spring action to swing the flagged end of an elongated indicator rod upward as a latch means attached to the mailbox front door releases the flagged end when the mail carrier opens the mailbox front door. The snappy, upward swing action and resulting residual vibration of the flagstaff caused by the coiled spring action may not be pleasing to the mail carrier.